A reclining mechanism of a vehicle seat according to the related art includes a perfectly circular ring member with an arc gear formed on the inner circumference thereof and a lock member including a lock gear unit engaging with the inside of the arc gear. The lock member is secured to a center shaft. It enters a locked state if it is pressed by a cam unit disposed in the ring member and thus engages with the arc gear but enters an unlocked state if the lock member is separated from the ring member.
Also, there is also known a vehicle seat in which a walk-in mechanism is operationally connected to the reclining mechanism and a vehicle seat can move forward if a seatback is tilted forward to release a locked state of a slide mechanism.
Moreover, in the related art, there is known a reclining apparatus with a memory mechanism, in which, when a seatback in a forward tilted state is rotated backward, the rotation is stopped if the seatback returns to its original state.    Patent Document 1: JP 2004-155228A1    Patent Document 2: JP 2005-103137A1    Patent Document 3: JP 2004-173922A1